1. Field of the Invention
The invention is in the field of pollution control and combustion efficiency relating to the combustion of carbon-containing fuels. More particularly, the present invention is in the field of increasing combustion efficiency in order to eliminate or reduce the quantity of combustion products like soot, hydrocarbons, carbon monoxide and other pollutants that are otherwise produced by internal combustion engines, such as diesel engines, and industrial burners, such as those that burn coal, fuel oil or other carbon-containing fuels.
2. Review of the Relevant Technologies
Modern society has mastered the art of producing new goods but struggles to dispose of its wastes. One problem associated with the modern economy involves pollutants that are produced by burning carbon-containing fuels, mainly fossil fuels, such as by internal combustion engines and industrial burners. The incomplete combustion of carbon-containing fuels such as gasoline, diesel fuel, fuel oil, coal, wood, biomass and even natural gas can result in the generation of pollutants such as carbon particulates, hydrocarbons, soot, oily substances, carbon monoxide (CO) and other pollutants. Such pollutants collect in the atmosphere and can cause all manner of health problems and smog. In response to the build-up of atmospheric pollution governments have attempted to legislate strict controls on the output of pollution generated by carbon-containing fuels.
In response to pollution caused by gasoline-powered internal combustion engines, catalytic converters have been developed and mandated to reduce the levels of incomplete combustion pollutants emitted into the environment by gasoline-powered vehicles. Catalytic converters are typically positioned in-line with the exhaust and muffling system of an internal combustion engine and are generally able to catalytically convert most of the unburnt hydrocarbons and CO into CO2 and water. Conventional catalytic converters contain palladium or platinum, which are coated on top of carrier beads or pellets made of inert and heat-resistant materials such as ceramics in order to increase the surface area of the active catalyst and keep them from simply blowing out the exhaust pipe.
Although modern catalytic converters can be used to convert unburnt hydrocarbons and CO into carbon dioxide (CO2) and water, they are generally only feasible for use with relatively clean burning systems such as gasoline-powered vehicles. They generally are not suitable for use with diesel engines. Because of the nature of diesel engines, both in terms of the fuel that is burned, as well as the way in which the fuel is burned, diesel engines produce substantial quantities of soot and other unburnt hydrocarbons which are too plentiful to be efficiently converted into CO2 and water using reasonably sized and priced catalytic converters known in the art. As a result, researchers have struggled for years to find an effective and economical way to remove pollutants from the exhaust stream of diesel engines.
More recently, public concern has translated into increased political pressure to strengthen emission standards for diesel engines. There is a possibility that emission guidelines will be imposed in certain states that may be difficult, if not impossible, to meet in an economically feasible manner. As a result, there is an acute need to develop improved diesel engines that are able to run more efficiently and produce less pollution that must otherwise be removed from the waste exhaust stream.
Besides diesel engines, researchers have struggled to find ways to effectively and economically address the tremendous quantity of pollutants generated by industrial burners, such as those that burn coal, fuel oil, or natural gas. In response to pollution controls directed to industrial burners, sophisticated scrubbers and after burners have been developed in attempts to satisfy such pollution standards. However, these and other pollution reduction means can be quite expensive, both in retrofitting older industrial burners as well as in the fabrication of new ones.
Even assuming one could construct a perfectly effective catalytic converter for carbonaceous particulates, hydrocarbons and CO, the end result would still be the generation of equal or greater amounts of CO2 compared to what is presently being generated. Although inert and non-polluting, CO2 is still of concern to environmentalists due to the fear that the buildup of excessive amounts of CO2 in the atmosphere has resulted in detectable global warming, although a minority of scientists remain skeptical, and will eventually result in catastrophic climatic changes if the world continues to generate CO2 in high quantities. Since there does not appear to be any end in sight of the need to burn fossil fuels, the concentration of CO2 will invariably continue to increase indefinitely.
In view of the foregoing, it would be an advancement in the art to provide methods and systems that could effectively and inexpensively eliminate, or at least substantially reduce, the quantity of unburnt or partially burnt combustion products produced by diesel engines and other internal combustion engines in an economically feasible manner.